Thermostatic switch



April 25, 1933; H, G. DYBVIG 1,905,823

THERMOSTATIG SWITCH Filed Feb, 27, 1930 Patented Apr. 25, 1933 UNITED STATES PATENT OFFICE HENRY G. DYBVIG, OF-DAYTON, OHIO, ASSIGNOR TO DELCO- PRODUCTS CORPORATION, OF DAYTON, OHIO, A CORPORATION F DELAWARE THERMOSTATIC SWITCH Application led February 27, 1930. Serial No. 431,758.

This invention relates to thermostatic switches. y

It is among the objects of the present 1nvention to provide a thermostatic switch of 6 simple structure and design, capable of being produced commercially at a minimum expense of time and material and which will eiiiciently control an electric circuit in response to variations in temperature condi- 10 tions. i

Further objects and advantages of the present invention Will be apparent from the following description, reference being had to the accompanying drawing wherein a preferred embodiment of one form of the present invention is clearly shown.

In the drawing: Fig. 1 is a plan View of the switch, certain parts being shown in section more clearly to illustrate interior structures.

Fig. 2 is a longitudinal sectional view taken substantially along the line 2--2 of Fig. 1, showing the switch in one operating position.

Fig. 3 is a view similar to Fig. 2, showing lthe switch in another operating position.

Referring to the drawing, the numeral 2O designates a housing or casing made up of any suitable insulating material such as molded condensation product. In the bottom wall of the housing 20 and adjacent one end thereof there is provided a terminal stud 21. This stud 21 has a head 22 inside the switch housing and under this head is clamped a blade spring 23, U-shaped as shown in Figs.

2 and 3. A Contact 24 is carried adjacent the free end of this blade spring 23. Another terminal stud 25 is provided in the housing at the opposite end thereof, said terminal being recessed inside the housing 20 for receiving the angular end 26 of the U-bar branch 27.

The U-bar as a Whole is designated by the numeral 28. The other branch 29 of the U- bar 28 has an angular portion 30 extending directly opposite the angular branch extremity 26, this branch 30, however, extend` ing into a recess formed in the housing 20.

The directly opposite angular ends 26 and 30 respectively of the U-bar 28 extending into these recesses, hingedly support said U-bar 28 within the housing 20. The intermediate portion 31 of the U-bar which connects the. two branch portions 27 and 29, has a clip 32 secured thereto in any suitable manner, preferably by welding. Upon this clip 32, contact 33 is mounted so that upon certain movements of the U-bar 28 said Contact may engage the Contact 24 on the blade spring 23.

A bi-metallic strip 40 is anchored at one end to the housing 20. The other end of the bi-metallic strip 40 has one end of a pressure spring 41 attached thereto, the other end of said pressure spring being anchored to the clip 32.

The bi-metallic strip 40 is adapted to Hex from one positionv into another in response to temperature changes. These temperature changes may be caused by a heater element (not shown) carried in the casing and heated by either the load current or a portion of the load current so that as the load currents become excessive the heater element increases in temperature. At room temperatures, the bi-metallic strip 40 will be iiexed into the position as shown in Fig. 2 in which position the spring 41 urges the U-bar 28 so that its contact 33 will engage with the contact 24 on the spring blade 23. The spring blade 23 is less stii than the compression spring 41 so that when the device is in the position as shown in Fig. 2, the spring blade 23 will be urged against the inner end of the terminal stud 21, thereby limiting the movement of the U-bar in this direction. As soon as the temperature increases the bi-metallic strip 40 Will flex in the opposite direction or toward the position in which it is shown in Fig. 3. In iiexing in this direction the bimetallic strip 40 will move so that spring 41 and strip 40 Will be in substantial alignment, in which instance the U-bar 28 Will start to move toward the left as regards Fig. 2. This initial movement of the U-bar 28 toward the left permits the spring blade 23 to move its Contact 24 to follow the slowly moving Contact 33 on the U-bar, thus contact engagement will be maintained until the I bi-metallic strip 40 moves to the right of the aligned position mentioned, at which instant the toggle eii'ect of the spring 41 will snap 10U the U-bar 29 into the position as shown in Fig. 3, or what might be termed the contact disengagin position. It will be seen that the spring lade 23 is not able to move the Contact 24 completely to follow the contact 33 so that at some time in the movement of the U-bar 29 toward the left as regards Fig. 3, a quick break will obtain between the two contacts 33 and 24.

It will of course be understood that with decreasing temperatures the thermostatic strip 40 will flex again toward the position as shown in Fig. 2 in which instance the spring 41 and the thermostatic strip 40 are again brought into alignment, and as soon as the thermostatic strip 40 moves out of alignment on the left side thereof, the spring 41 will quickly urge the U-bar 28 toward the right as .regards Fig. 3 or into the position as shown in Fig. 2, which is termed the contact closing position.

From the aforegoing it may be seen that applicant has provided a switch of simple structure and design, capable of being produced at a minimum expenditure of time and material and which will eiliciently open and close an electric circuit in response to varyin temperatures.

hile the form of embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. A thermo-switch comprising, in combination, a housing having two parallel walls provided with aligned, oppositely disposed openings, one of said openings having connecting means therein, a contact carrier having oppositely disposed arms extending into the said openings of the housing Walls respectively whereby said contact carrier is pivotally supported at one end within the, housing; a thermostatic member` anchored at one end within the housing; a compression s ring interposed between the free ends of the thermostatic member and carrier and adapted to shift the carrier from one position in the housing into another in response to movement of the thermostat; and a switching means comprising a stationary contact on the housing and a cooperating contact on the carrier.

2. A thermo-switch comprising, in combination, a housing of insulating material; a terminal plug in one wall of the housing, said plug having a central opening at its inside end; an opening in the opposite wall of the housing aligned with the opening in the lug; a U-shaped, wire member having its en portions bent so as to be oppositely disposed, one end fitting into the opening in the housing wall, the other into the opening in the plug, whereby said member is pivotally carried Lacasse within the housing; a contact at the closed end of the U-shaped member; a contact carried by the housing so as to be engageable by the contact on said member; a bi-metallic strip anchored at one end to the housing adjacent the pivotal support of the member; and a compression spring interposed between the free end of the strip and the closed end of the U-shaped member.

3. In a temperature controlled switch, the combination comprising, a housing, a thermostatic member anchored at one of its ends to said housing and adapted to flex in response to temperaturev changes, a terminal plug mounted on said housing and having a recess therein, a recess in said housing, a contact carrying member pivotally mounted in said recesses, resilient means coupling one end of said thermostatic member to said contact carrying member, a terminal mounted on said housing, and a resilient contact carrying member connected with said terminal and actin against said resilient means when said switc is closed.

4. In a temperature controlled switch, the combination comprising, a relatively straight thermostatic element, a contact carrying member having oppositely disposed arms,

lmeans including said arms for providing a pivotal mounting for said contact carrying member, means for making electrical connection with one of said arms, elastic means coupling said thermostatic element and said contact carrying member, and acontact having a resilient mounting, said resilient mounting providing means for aiding the action of said thermostatic element and elastic means.

5. In a thermostatically controlled switch, the combination comprising, a housing, a bimetallic strli) anchored at one end to said housing, a -shaped contact carrying member pivotally mounted at points on said housing adjacent the anchored end of said bimetallic strip, a contact mounted on said contact carrylng member away from said pivotal mounting, a cooperating contact resiliently mounted on said housing, resilient means coupling the free end of said bimetallic stri and said contact carrying member, said bimetallic stri passin through the plane of the sides o said U-Eliaped member in operation.

6. In a thermostatically controlled switch. the combination including, a mounting, a bimetallic stri anchored at one end to said mounting, a -shaped contact carrying member pivotally mounted at points on said mounting adjacent the anchored end of said bimetalhc stri ,means including a fixed connector plug orl making connections with said contact carrying member, a contact mounted on said ,contact carrying member away from the pivotal mounting, a cooperating contact resiliently mounted on said mounting, and resilient means covpling the free end of said bimetallic strip and said contact carrying member, said bmetallic strip flexing intermediate the sides of said U- shaped member in response t0 temperature l(zhange, to actuate the contact carrying mem- In testimony whereof I hereto aix my signature. t

HENRY G. DYBVIG. 

